The processing of an integrated circuit chip or wafer normally includes the steps of:
1. Selective polymerisation of a photo sensitive layer using an electron beam (direct writing on wafer). PA0 2. Opening doping windows using the polymerized layer as a mask and etching away an insulating layer (Sio.sub.2, Si.sub.3 N.sub.4, etc. . . . ) PA0 3. Doping selected areas of the semiconductor using ion implantation or solid state diffusion (the so called predeposition step). PA0 4. Bringing the dopant ions to substitutional sites (electrical activation of the dopant) using thermal annealing. This involves a non localized heat treatment of the whole substrate material (wafer) in a diffusion furnace or a rapid thermal annealer (RTA).
If selective oxidation is required, an oxygen beam is employed in step 3, and then heat treatment in step 4 creates covalent bonding of the oxygen ions.
A disadvantage of the above process is that the annealing stage is time consuming and can create problems, such as warping of the wafer.